The lack of scientific research into atmospheric backpressure in wood burner standards will always mean smoke on cold nights and in mornings. Lab based testing on appliances ignores it and the whole change-out scheme loses credibility over the American EPA/ Lung Association's influence on the scheme (perhaps via the Trans Pacific Partnership with USA policy). The scheme born out of Energy Security policies favours central energy suppliers that increase demand for profit. Is it a shock to anyone that air conditioners are being promoted over the country. How big is that mound of plastic at Christchurch's landfill? Pellet burners - the only appliances allowed in zone 1 areas need electricity to start and manufactured wood pellets to burn. A chimney cowl invented in this country solves the polluting issue of back pressure. The result is zero emmissions in most cases in less than 3 minutes. Because the changeout schemes are political it struggles to get recognised by it. No laws exist on chimney cowls yet council inspectors have been told in some areas not to pass it for permit. No testing apparatus at BRANZ is suitable for it as wood heating appliances are tested in 'ideal' lab conditions without the flue exposed to real life atmospheric conditions. The wood heater is not the enemy here. The self sufficient, carbon neutral, renewable, sustainable benefits of all biomass heating outway the exagerated-untested health dissadvantages publicised. Make sure at the end of the night to only have embers. Don't completely shut the air damper - ever! You should still be able to keep the embers hot with the air vent slightly open. If not you need to look at the options out there.